Solar energy conversion technologies: principles and advancements

Ajarostaghi, Seyed Soheil Mousavi; Mousavi, Seyed Sina

doi:10.1016/b978-0-323-89866-9.00005-5

Cited by 5 publications

(5 citation statements)

References 119 publications

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“…The instantaneous efficiency was calculated and compared for the different tilt angles and mass flow rates using Equation (3) [38]. Other parameters are calculated using Equations ( 4) - (7). ASHRAE Standards were referred to, while calculating the efficiency to ensure accuracy in the results.…”

Section: Solar Collector Performance: Governing Equationsmentioning

confidence: 99%

“…A broad categorisation of the technology is shown in Figure 3 with respect to concentration and operational temperatures. While low-temperature solar thermal collectors (STC) such as unglazed flat plates are generally used to heat swimming pools, the mediumtemperature glazed flat-plate and evacuated tube collectors are used for air and water heating applications in buildings [7]. In order to improve the efficiency of a solar thermal collector, researchers proposed a concept of directly absorbing the solar energy within the fluid volume in the 1970s called Direct Absorption Solar Collector (DASC) [9].…”

Section: Introductionmentioning

confidence: 99%

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Direct Absorption Solar Collector: An Experimental Investigation of Al2O3-H2O Nanofluid over the Flat Plate at Different Tilt Angles, and Mass-Flow Rates

Jyani,

Sharma,

Chaudhary

et al. 2024

New Energy Exploit. Appl.

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The escalating demand for solar thermal energy, coupled with the current inefficiencies in existing systems, underscores the critical need for innovative advancements in thermal storage solar collectors. The efficiency of solar collectors relies not solely on design effectiveness but also on the thermophysical properties, such as heat capacity and thermal conductivity, inherent in the working fluid. This study investigates a novel solar collector with a gross area of 0.36 m2, operating on the principle of direct absorption. Experimental investigations were done at various tilt angles (15°, 20°, and 30°) with respect to the horizontal, considering different flow rates and nanofluid settlement within the base fluids. The use of Al2O3 nanoparticles into the base fluid as water, exhibits significant positive effects on the thermophysical properties of the nanofluids, with a volume concentration of 0.003%. The efficiency of the solar collector was calculated across three mass flow rates (0.5, 1, and 1.33 L/min) at each tilt angle. Notably, the study reveals that the efficiency peaks at a 15° tilt due to an optimal flow configuration for maximum energy harvest across all three mass flow rates. Increasing the mass flow rate yields efficiency increments for all tilt angles (15°, 20°, and 30°), with 1 L/min emerging as the optimal mass-flow rate in most cases. This research not only addresses the immediate need for improved solar thermal technologies but also aligns with global sustainability goals, contributing to the IEA Net Zero Emissions initiative and supporting UN Sustainable Development Goals 7, 9, and 11. The paper also includes a critical literature review on the use of nanofluids in solar thermal collectors to improve thermo-physical properties and enhance solar efficiency. Additionally, the key findings regarding the influence and tilt angle on solar efficiency are discussed.

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Section: Solar Collector Performance: Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Direct Absorption Solar Collector: An Experimental Investigation of Al2O3-H2O Nanofluid over the Flat Plate at Different Tilt Angles, and Mass-Flow Rates

Jyani,

Sharma,

Chaudhary

et al. 2024

New Energy Exploit. Appl.

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“…Thus, several studies have been conducted from different perspectives. Ajarostaghi et al [13] studied the performance of a single U-shaped vertical buried pipe heat exchanger by numerical simulation. The results show that the inlet volume flow, the inlet fluid temperature, and the backfill material's thermal conductivity significantly impact the thermal performance of the buried pipe heat exchanger.…”

Section: Introductionmentioning

confidence: 99%

Heat exchange characteristics of underground and pavement buried pipes for bridge deck heating conditions

Zheng,

Song,

Ding

2024

PLoS ONE

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Geothermal energy is increasingly employed across diverse applications, with bridge deck snow melting emerging as a notable utilization scenario. In Jinan city, China, a project is underway to utilize ground source heat pumps (GSHPS) for heating bridges. However, essential operational parameters, including fluid medium, temperature, and heat exchange details, are currently lacking. This study addresses the thermal design challenges associated with ground heat exchangers (GHE) for bridge heating through a combination of numerical modeling and field experiments. Utilizing software Fluent, a refined three-dimensional multi-condition heat transfer numerical analysis was carried out. Field tests based on actual operating conditions were also conducted and the design parameters were verified. The results indicate that an inlet temperature of 5°C and an aqueous solution of ethylene glycol with a mass concentration of 35% as the heat exchange medium are suitable for the GSHPS in Jinan; Moreover, the influence of backfill material and operation time on the heat transfer efficiency was revealed and the suitable material with 10% bentonite and 90% SiO2 was suggested; Finally, based on the influence of the pipe spacing on the heating characteristics of bridge deck, the transition spacing of 0.2 m is given for the temperature response of the bridge deck. This comprehensive study contributes valuable insights through simulation and experimental analysis of the thermal environment variation, aiming to advance the development of GSHPS for bridge deck heating in Jinan, China.

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“…Today, fossil energies are widely used in various industries, but due to the lack of these energies and the environmental pollution caused by their use, societies have turned to using clean and renewable energies such as solar energy [1][2][3], wind energy [4], and geothermal energy [5][6][7]. The use of these energies requires comprehensive and complete information regarding the design and operation of renewable energy converters.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Double Stack Blade Savonius Wind Turbine with Secondary Blades

Ajarostaghi

Mousavi

Bhojaraju³

2023

IOP Conf. Ser.: Earth Environ. Sci.

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In this work, the performance of the Savonius vertical axis wind turbine with secondary blades was investigated numerically. The impacts of two geometric parameters of the secondary blades, including the height of secondary blades (h) and the distance between the main and the secondary blades (b) on the output torque were analyzed. Numerical simulations were performed by a commercial CFD code, ANSYS FLUENT 18.2. Numerical results show that employing secondary blades has a constructive impact on the output torque compared to the case without secondary blades. Moreover, the studied geometric parameters of the secondary blades have a significant impoact on the performance of the proposed turbine. It can be seen that by increasing the height of secondary blades, the angular position of the maximum torque is shifted. At b = 2.5 mm, the difference between the models is more comparable. Models h = 6 and 12 mm have the highest output torque, although with a slight difference between them. Model h = 12 mm has the highest output torque. At b = 7.5 mm, the difference between the models is more comparable than b = 2.5 mm. Model h = 12 mm has the highest output torque and models h = 3 and 6 mm are in the next levels. Obtained results in the second section demonstrate that by growing the distance between the secondary and the main blades, in the case of h = 3 mm, the produced torque declines. Furthermore, by increasing the distance between the secondary and the main blades from b = 0 mm to b = 2.5 mm and b = 7.5 mm, the amount of torque produced decreases by 17.33 and 26.66%, respectively. Moreover, by augmenting the distance between the secondary and main blades from b = 2.5 mm to b = 7.5 mm (200% growth), the produced torque decreases by 11.3%.

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Solar energy conversion technologies: principles and advancements

Cited by 5 publications

References 119 publications

Direct Absorption Solar Collector: An Experimental Investigation of Al2O3-H2O Nanofluid over the Flat Plate at Different Tilt Angles, and Mass-Flow Rates

Direct Absorption Solar Collector: An Experimental Investigation of Al2O3-H2O Nanofluid over the Flat Plate at Different Tilt Angles, and Mass-Flow Rates

Heat exchange characteristics of underground and pavement buried pipes for bridge deck heating conditions

Numerical Analysis of Double Stack Blade Savonius Wind Turbine with Secondary Blades

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